Texas, I'll edit one in. And I apologise in advance.
EDIT: Oh, and I reserve Magikarp. Yes, it is going to be fun. I also reserve Morty.
Double EDIT:
Okay. Firstly, get yourself a Magikarp, called Magikrap, which can only be changed after it evolves, at which point it can be whatever you want because I think you will need some concession. You catch this Magikarp as soon as you can, because you will want to train it as much as possible. Specifically, you will want to train it until it can solo one of Morty's Pokemon (Struggle can hit Ghosts, if you're interested). On the way, though, it has to be the only Pokemon you use on the way through Union Cave to train it up, and you must defeat every Pokemon you get to. If it faints, you must go straight back to the Pokemon Centre without passing go and try again.
Eventually you will beat Morty, with one of his Pokemon soloed by Magikrap. After this, you must head West along the storyline, and can ignore Magikrap for a bit, unless you feel like soling Jasmine (No, not compulsory, just fun). Eventually, you will meet the Red Gyarados, and to prove that it is not too Magikrap it must solo this as well. It must finish Gyarados using Flail. Then you will go up against Pryce, against whom Magikrap must Splash five times, at which point it must solo a Pokemon again, and then do the same thing again. Finally, it can finish off its Johto travels by finishing half of Lance's Pokemon. At this point, it can evolve. Lucky you. Just in time for some fresh horror in the Kanto region. You will be allowed to learn more than Splash, Tackle and Flail soon, I promise.
Congratulations, first of all. Johto wasn't fun. To celebrate, you only have to solo every trainer in the Electric-type gym without going to the Pokemon centre. If you fail... well we'll go into that later. Then you can continue on your adventure, until you get to the Fire-type gym. Here, you must use Splash again for every Fire-type move the trainers use to compensate for the resistance. You have to solo every trainer again. You may NOW, regardles of success in the gym, delete Tackle or Flail, but never Splash, and replace it with a Water-type move.
Now we get to near the end of your travels. After the last badge, you can replace the two moveslots that are not the Water-type move and Splash. They are now Thunder and Fire Blast, assuming you succeeded at beating those trainers. If not, you can only have the one that you did succeed in, and the first move you must delete is the one which is not Tackle. You must solo three Pokemon belonging to Red, but you can only use each of the moves over 50 base power once each. You must also use Splash against Pikachu.
There. That should be just about it. Do you think that looks hard? I think so. But it isn't impossible, so can't use items. Have fun.